Ⅰ M'lachim, chapter 6, describes part of the building of the first bes hamikdash. What follows is a rough translation in line with the commentaries.

First, though, note that the structure was divided into two rooms, an inner room (which we usually call the kodesh kadashim) and an outer one (the kodesh). The two rooms were separated by a partition called, in this chapter, the d'vir. The inner room was 'inner' only in the sense that you went through the outer room to get to it: in fact, they were parallel to one another, each occupying the full width of the structure, the outer room first and the inner room second as in a shotgun house. The inner room was twenty cubits deep from front to back.

[After building the actual structure, which was stone,]15 he built the walls inside of erez-wood planks: from floor to ceiling he coated [the stone walls] with wood inside. And he coated the [stone] floor with b'rosh-wood planks.16 The end of the structure, the last twenty cubits, he built with erez-wood planks from floor to ceiling.…18 The erez wood inside the structure was decorated with [shapes]. All was erez wood: no stone was visible.…20 Beyond the d'vir… he coated with purified gold….21Sh'lomo coated the inside of the kodesh with purified gold.…22 He coated the entire structure with gold, the entire structure [=even the ceiling].…29 He decorated the [wooden planks covering the] walls of the structure with [shapes], both in the inner room and in the outer room.

What's with all the repetition?

Verses 15 and 16 could easily be combined to say he covered the walls of the whole structure (both rooms) with wooden planks.

Likewise, verses 20 and 21 could be combined to say he gilded the walls of the whole structure (both rooms).

More so, why does verse 22 repeat that he gilded the structure after verse 21 says so? Sure, the commentaries say verse 22 is singling out the ceiling. But why does it need to single out the ceiling instead of discussing it with the walls?

Most of all, why does verse 29 repeat what verse 18 said already? Again, verse 18 is (seemingly) speaking of only the outer room whereas verse 29 speaks of both rooms, but (a) it's repeating verse 18 with respect to the outer room and (b) anyway, why discuss them separately? They can easily be combined into verse 29.